Do we learn to adapt? Daily-based force adaptation in infants, children and adults
Wed-H6-Talk 7-7502
Presented by: Laura Faßbender
Humans are kinematic artists who adapt their movements flexibly to rapidly changing task conditions when experiencing mismatches between motor planning and actual task outcomes. Already in the first year of life, infants anticipate the weight, shape and size of objects in order to grasp them as efficiently as possible. However, little is known about the development of motor adaptation. In this study, we tested force adaptation in 1.5-year-old infants, 3-year-old children and young adults. Participants opened a drawer whose resistance was temporarily perturbed. In groupLHL, participants experienced a low (trials 1-12) to high (trials 13-24) to low (trials 25-36) drawer resistance; and in groupHLH, the sequence was reversed. The main dependent variable was the drawer opening peak speed. As expected, the change of drawer resistance decreased the drawer peak speed in the first adaptation trial (i.e., trial 13) of groupLHL and increased it in groupHLH. In the subsequent adaptation trials (i.e., trial 14-24) all age cohorts of groupLHL returned to their baseline drawer peak speed, while in groupHLH their peak speed remained above their initial baseline. Thus, only groupLHL revealed force adaptation. Although motor performance differed across age cohorts with infants and children having a higher movement variability and lower efficiency of the drawer velocity profile, no age effect on adaptation performance was found. Overall, it appears that even 1.5-year-old infants form internal models of force parameters and show adaptive performance when task requirements are unexpectedly changed.
Keywords: motor adaptation, internal model, development, motor skills